What could be wrong: pain in left hip area for 2 weeks?

i started having this pain in my left hip area almost 2 weeks ago now. it feels kind of like a cramp and its only mild pain but if i put weight on my left foot and then stand normal again i have a sharp pain. i thought it had gotten better yesterday because there was almost no pain but today i had basketball training and now it feels worse and the pain has spread into my backside area as well as my hip. what could be wrong with me??